Process for breaking petroleum emulsions



Patented Jan. 2?,

NITED STAE FTENT OFFICE lei-win Grocte, University City, Mo, assignor toPetrciite tlorporaticn, a corporation of Dela- No Bray ing. ApplicationDecor-amber l, 1950, Serial No. 1%,754

9 @iaims. l

The present invention is a continuation-impart of my co-pendingapplication, Serial No. 104,801 filed July 14, 1949 (now Patent2,552,528, granted May 15, 1951). This invention relates to petroleumemulsions of the water-in-oil type that are commonly referred to as cutoil, roily oil, emulsified oil, etc, and which comprise line droplets ofnaturally-occurring waters or brines dispersed in a more or lesspermanent state throughout the oil which constitutes the continuousphase of the emulsion.

One object of my invention is t process for breaking or resolving kindreferred to.

Another object of my invention is to provide an economical and rapidprocess for separating emulsions which have been prepared undercontrolled conditions from mineral oil, such as crude oil and relativelysoft waters or weak brines. Controlled emulsification and subsequentdemulsificaticn under the conditions just mentioned are of significantvalue in removing impurities, particularly inorganic salts from pipelineoil.

Demulsification as contemplated in the present application includes thepreventive step of comingling the demulsifier with the aqueous componentwhich would or might subsequently become either phase of the emulsion,in absence of such precautionary measure. Similarly, such demulsiliermay be mixed with the hydrocarbon component.

The demulsifying agent employed in the present process is a fractionalester obtained from a polycarboxy acid and a tetralol, i. e., thechemical compound having i alkanol hydroxyls comparable to diols andtriols. The particular hydroxylated compound herein employed is obtainedby reaction between a polypropylene glycol of comparatively highmolecular weight, for example 750- 5,000, with two moles of glycide,thus converting a dial into a tetralol.

A polypropylene glycol may be indicated by the following formula:

0 provide a novel envisions of the with the proviso that n is a largenumber sufficient to bring the molecular weight range of thepolypropylene glycol within the molecular weight range of '750-5,0i)0.

Incidentally, my preferred range is approximately 1750 to 2756.

If one mole of such diol were etherized with 2 moles of glycerol or,what amounts to the same thing, reacted with 2 moles of glycide, thereac- 2 tlon product, or at least one of the reaction products may beindicated as follows:

HO OH olnaourmnoon HO OH It would be immaterial as to the form of thetetralol and, as a matter of fact it well may be that cogeneric mixturesare obtained. Thus, it is more satisfactory to indicate the tetralol asbeing of the following composition:

with the proviso that R is a radical selected from the monovalentradicals consisting of hydrogen,

OH CaHEY and OH CaH5 OH OC3H5 to form a tetralol.

Polypropylene glycols are available from at least two companies. Suchpolypropylene glycols are furnished in various molecular weight ranges.The water-insoluble, kerosene-soluble polypropylene glycols being in themolecular weight range somewhere above 500, and more specifically,starting at about 700 or 750. The molecular weight was usuallydetermined by the hydroxyl method. Such hydroxyl molecular weight is afraction, sometimes a large major fraction,

of the theoretical molecular weight based on the method of synthesis, 1.e., the calculated molecular weight based theoretically on the value onewould expect to obtain by treating water or propylene glycol, forexample, with propylene oxide. Needless to say, one does not obtain asingle compound but a polypropylene glycol of a molecular weight ratioof 750 or 1,000 or 2,000 as the case may be, which really represents acogeneric mixture whose statistical average molecular weight is the oneindicated.

Polypropylene glycols, which are regularly supplied to the trade involume, include those where the molecular weight runs to 2,000 andbeyond. Higher ones are available up to a molecular weight of 3,000 ormore. Those of molecular weight of 3,000 to 5,000 can be prepared byconventional means employing substantially the same procedure as producepolypropylene glycols available on the market. In any event thoseavailable on the market, for instance, polypropylene glycol 2,000, issubstantially in the center of the preferred range (1750-2750) and thusis perhaps the outstanding raw material commercially available for theherein described purpose.

If a polycarboxy acid for convenience is indi cated thus:

COOH

in which n is a whole number not greater than 2, it becomes obvious thatthe resultant obtained from treating one mole of the tetralol with 4moles of a polycarboxy acid may be written thus:

in which all the characters have their previous significance, with theproviso that is the tetravalent radical obtained, at leasthypothetically, by the elimination of the hydroxyl hydrogen atoms fromthe tetralol R'O-(RO) nR' as previously described, with the proviso thatn represents a whole number varying from one to three and the sum ofboth occurrences of n" is 4.

It is obvious that minor changes can be made which do not detract fromthe spirit of the invention, for instance, one could start with a moleof ethylene glycol or mole of diethylene glycol and oxypropylate so asto get a compound which in the strictest sense of the world is not apolypropylene glycol but for all herein mentioned purposes would meetthe requirement as to molecular weight range and solubility. Similarly,one could start with butylene glycol and react with a mole of ethyleneoxide and then follow by oxypropylation so as to give a product whichagain in its strictest sense might not be a polypropylene glycol but yetwould be Within the molecular weight range and show the same solubilitycharacteristics and be entirely satisfactory. For all practical purposessuch compounds are considered as polypropylene glycols for the hereindescribed purpose.

Having obtained the tetralol of the kind described the product soobtained is converted into an acidic ester by reacting with apolycarboxy acid so as to introduce one mole of the acid for I eachhydroxyl radical. This is shown by the above formula. Suchesterification is conducted under comparatively mild conditions toprevent polymerizing, i. e., the final product is an acidic ester of thehydroxylated material and not a polyester. For convenience, what is saidhereinafter will be divided into five sections:

Part 1 is concerned with the preparation of the tetralol from theselected polypropylene glycol;

Part 2 is concerned with the preparation of the esters from thetetralol;

Part 3 is concerned with the structure of the esterifieclpolyhydroxylated compounds and particularly from the standpoint of thepolypropylene glycol itself and its relationship to the ultimatedemulsifiers;

Part 4 is concerned with the use of the products herein described asdemulsifiers for breaking water-in-oil emulsions, and

Part 5 is concerned with certain derivatives which can be obtained fromthe tetralols. In some instances such tetrahydroxylated compounds can bereacted further and converted into other intermediates which in turn canbe reacted further, as for example, by modest oxyethylation, than withthe same polycarboxy acids and anhydrides as described in Part 2, togive efiective demulsifiers.

PART 1 As previously stated the initial step in the manufacture is toeither prepare a polypropylene g ycol of roughly 750-5000 molecularweight which is water-insoluble and kerosene-soluble, or else topurchase such material in the open market. My preference is to purchasesuch material in which the molecular weight is 2,000 or slightly higher.The next step is to convert this diol into a tetralol by treatment with2 moles of glycide. Needless to say, other reactions can be employedwhich do not involve glycide as, for example, one can produce ethers ofthe kind herein employed by use of a glycerol monochlorohydrin, eitheralphaor betamonochlorohydrin. Attention is directed to the fact that itwould be immaterial as to whether a derivative were 0-btained from thealphaor betaglycerolmonochl-orohydrin. Similarly, a similar isomericdifference can occur depending on ho'v the epoxy ring is ruptured in thecase of glycide. Other suitable procedures involve the use ofepichlorohydrin in the conventional manner. In some instances this wouldinvolve an intermediate step of converting the diol into an alkoxide.Other procedures would involve the use of epichlorohydrin with theresultant product treated with caustic soda so as to reform the epoxyring. The epoxide so obtained could then be treated with water to yielda compound having more than one hydroxyl radical, at least, one of thetwo initial terminal hydroxyls attached to the polypropylene glycol.

Attention is directed to the fact that the use of glycide requiresextreme caution. This is particularly true on any scale other than smalllaboratory or semi-pilot plant operations. Purely from the standpoint ofsafety in the handling of lycide, attention is directed to thefollowing: (a) If prepared from glycerol monochlorohydrin, this productshould be comparatively pure; (b) the glycide itself should be as pureas possible as the effect of impurities is difficult to evaluate; (c)the glycide should be introduced carefully and precaution should betaken that it reacts as promptly as introduced, 1. e., that no excess ofglycide is allowed to accumulate; (d) all necessary precaution should betaken that glycide cannot polymerize per se; (e) due to the high boilingpoint of glycide one can readily employ a typical separatable glassresin pot as described in U. S. Patent No. 2,499,370, dated March 7,1950, to De Groote and Keiser, and offered for sale by numerouslaboratory supply houses. If such arrangement is used to preparelaboratory-scale duplications, then care shou d be taken that theheating mantle can be removed rapidly so as to allow for cooling; orbetter still, through an added opening at the top, the glass resin potor com parable vessel should be equipped with a stainless steel coolingcoil so that the pot can be cooled more rapidly than by mere removal ofmantle. If a stainless steel coil is introduced it means thatconventional stirrer of the paddle type is changed into the centrifugaltype which causes the fluid or reactants to mix due to swirling actionin the center of the pot. Still better, is the use of a laboratoryautoclave f the kind offered for sale by a number of laboratory supplyhouses; but in any event, when the initial amount of glycide is added toa suitable reactant, such as a polypropylene glycol of the kinddescribed preceding, the speed of reaction should be controlled by theusual factors, such as (a) the addition of glycide; (b) the eliminationof external heat; and (c) the use of cooling coil so there is no unduerise in temperature. All the foregoing is merely conventional but isincluded due to the hazard in handling glycide.

Example 1a The equipment used was a glass pot of the kind abovedescribed. This particular pot had a capacity of about 1500 ml. Thepolypropylene glycol selected was a commercial product described aspolypropylene glycol 2025. This value was the same as the molecularweight based on the hydroxyl value. The ratio or glycide to diol isobviously 2 to 1 to produce a tetralol. The amount of polypropyleneglycol taken was one-half of a gram mole, i, e., 1015 grams. This wasreacted with one gram mole of glycide ('74 grams). The rocedure was asfollows: The polypropylene glycol was charged into the reaction vesselalong with 1% (10.5 grams) of sodium methylate. The mixture was stirredand the temperature raised to about 120 C. The glycide was introduceddropwise into the reaction mixture with constant stirring at acomparatively low rate, i. e., about 15 grams per hour. The entirereaction required approximately 5 hours. The temperature during thereaction was allowed to rise to 130 C. At any time it tended to gohigher it was cooled in an appropriate manner. If the temperature tendedto drop below 112 to 115 0., the reaction mass was heated. When all theglycide had been added the reaction mass was stirred for approximatelyan hour longer at 130 C. and then heated to a temperature below thedecomposition point of glycide, for instance, 140 0., and held at thishigher temperature for another hour. In this particular reaction therewas comparatively little hazard due to the small amounts of glycideinvolved. Even so, such oxyalkylation should be conducted with extremecare.

Example 2a The same procedure was employed except that a polypropyleneglycol having a molecular weight of 1750 was substituted for the productused in Example 1a. This meant the use of 875 grams of polypropyleneglycol and 9 grams of sodium methylate as a catalyst. The amount ofglycide em ployed was identical to that in Example 1a, and the rate ofaddition was the same. The temperature, conditions and the subsequentstirring after all the glycide was in were identical with thosedescribed in Example 1c, preceding.

Example 30.

The same procedure was followed as in Examples la and 2a, preceding,except that the polypropylene glycol used was one having a molecularweight of 2750. The amount employed was 1375 grams. The amount ofcatalyst employed (sodium methylate) was 14 grams. The amount of glycideemployed was identically the same as in Examples 10. and 2a, prece ing.The time factor and temperature were the same as in Examples 1a and 2a,precering. The heating period after all the glycide was in was the sameas in Examples la and 2a, preceding. In this instance, how ever, theglass reaction pot had a capacity of 2 liters instead of 1 /2 liters.

The tetralols resulting from the above proce' dures were slightlyoff-color compared with the original polypropylene glycol. A slightchange to a faint yellowish cast appeared during the reaction withglycide. The final product, of course, had a slightly alkaline reactiondue to the presence of sodium methylate and this would have been thecase also if some other catalyst, such as caustic soda, had been used.

These tetralols could, of course, be bleached in the usual manner with ableaching clay, a filtering char, or the like. For the purpose ofproducing the demulsii'ier this was immaterial. The viscosity of theliquids were somewhat higher than that of the initial diols from whichthey were obtained. These products, i. e., tetralols, werewaterinsoluble and kerosene-soluble.

PART 2 As previously pointed out the present invention is concerned withacidic esters obtained from tetralols described in Part 1, preceding,and polycarboxy acids, particularly dicarboxy acids such as adipic acid,phthalic acid, or anhydride, succinic acid, diglycollic acid, sebacicacid, azelaic acid, aconitic acid, maleic acid or anhydride, citraconicacid or anhydride, maleic acid or anhydride adducts as obtained by theDiels-Alder reaction from products such as maleic anhydride, andcyclopentadiene. Such acids should be heat stable so they are notdecomposed durin esterification. They may contain as many as 36 car bcnatoms as, for example, the acids obtained by dimerization of unsaturatedfatty acids, unsaturated monocarboxy fatty acids, or unsaturatedmonocarboxy acids having 18 carbon atoms. Ref erence to the acid in thehereto appendedclaims obviously includes the anhydrides or any otherobvious equivalents. My preference, however, i. to use polycarboxy acidshaving not over 8 carbon atoms.

The production of esters including acid esters (fractional esters) frompolycarboxy acids and glycols or other hydroxylated compounds is wellknown. Needless to say, various compounds may be used such as the lowrnolal ester, the anhydride, the acyl chloride, etc. However, forpurpose of economy it is customary to use either the acid or theanhydride. A conventional procedure is employed. On a laboratory scaleone can employ a resin pot of the kind described in U. S. Patent No.2,499,370, dated March '7, 1950 to'De Groote and-Keiser;andparticularlywith -one more opening-to permit the-use of a porous spreader ifhydrochloric acid gas is to be used as a catalyst. Such device orabsorption-spreader consists-of minute Alundum thimbles which areconnected to a glass tube. One can add a sulfonic acid such aspara-toluene sulfonic acid as a catalyst. There is some objection tothis because in some instances there is some evidence that this acidcatalyst tends to decompose or rearrange the oxypropylated compounds,and

particularly likely to do so if the esterification temperature is toohigh. In the case of polycarboxy acids such as diglycollic acid, whichis strongly acidic there is no need to add any catalyst. The use ofhydrochloric gas has one advantage over para toluene sulfonic acid andthat is that at the end of the reaction it can be removed by flushingout with nitrogen, whereas there is no reasonably convenient meansavailable'of removing the paratoluene sulfonic acid or other sulfonicacid employed. If hydrochloric acid is employed one need only pass thegas through at an exceedingly slow rate so as to keep the'reaction massacidic. Only a" trace of acid need be present. I have employedhydrochloric acid gas or the aqueous acid itself to eliminate theinitial basic material. My preference, however, is to use no catalystwhatsoever and to insure complete dryness of the tetralol as describedin the text immediately following.

The products obtained in Part 1 preceding may contain a basic catalyst.As a general procedure I'have added an amount of halfeconcentratedhydrochloric acid considerably in excess of what is'required toneutralize the. residual catalyst. The mixture is shaken thoroughly andallowed to stand overnight. Itfis then filtered and refiuxed' with thexylene present until the water can be separated in a phase-separatingtrap. As soon as the product is substantially free from water thedistillation stops. This preliminary step can be carried out in theflash to be used for esterification. If there is any further depositionof sodium chloride during the reflux stage needless to say a secondfiltration may be required. In any event the neutral or slightly acidicsolution of the oxypropylated derivatives described in Part 1 is thendiluted further with sulfioient xylene, decalin, petroleum solvent, orthe like, so that one has obtained approximately a solution. '-To thissolution there is added a polycarboxylated reactant as previouslydescribed, such as phthalic anhydride, succinic acid or anhydride,diglycollic acid, etc. The mixture is refluxed until esterification iscomplete as indicated by elimination of water or drop in carboxyl value.Needless to say, if one produces a half-ester from an anhydride such asphthalic anhydride; no water is eliminated. However, if

it is obtained from diglycollic acid, for example,

water is eliminated. All such procedures are conventional and have beenso thoroughly described in the literature that further considerationwill be limited to a few examples and a comprehensive table.

Other procedures for eliminating the basic residual catalyst, if any,can be employed. For

example, the oxyalkylation can be 'conductedin absence of a solvent orthe solvent removed after oxypropylation. Suchoxypropylati'on endprodnot can then be acidified with just enough concentrated hydrochloricacid to just neutralize the residual basic catalyst. To. this productone can then" add a small amount of anhydrous sodium water thatis'present) and then subject the mass to centrifugal force so as toeliminate the sodium sulfate and probably the sodium chloride formed.The clear somewhat viscous straw-colored amber liquid so obtained maycontain a small amount of -sodium sulfate or sodium chloride but, in anyevent, "is perfectly acceptable for esterification in the mannerdescribed.

It is tobe pointedout that the products here described'are notpolyesters in the sense that there'is a plurality of both tetralolradicals and acid radicals; the product is characterized by having onlyone tetralol radical.

In some instances and, in fact, in many instances I have found thatinspite of the dehydration methods employed above that a mere trace ofwater still comes through and that this mere trace of watercertainlyinterferes'with the acetyl or hydroxyl valuedetermination, at leastwhen" anumber of conventional procedures are used and may retardesterification, particularly where there is no sulfonic acid orhydrochloric acid present" as a' catalyst. Therefore, I have preferredto use the following procedure? I have employed about'200 grams of thetetralol as described-in Part 1, preceding; I have added about 60 gramsof benzene, and then refluxed this mixture in the glass resin pot usinga phase-separating trap until the benzene carried outall the waterpresent as water 'of'solution or the equivalent. Ordinarily thisrefluxing temperature' is apt to be in the neighborhood of to possiblyC. When all this water or moisture has been removed I also Withdrawapproximately 20 rams or a little less benzene and then add the requiredamount of the carboxy reactant and also about 150 grams of a highboiling aromatic petroleum solvent. These solvents are sold by variousoil refineries and; as far as solvent eifect act as if they were almostcompletely aromatic in character. Typical distillation data in theparticular type I'have employed and found very satisfactory is thefollowing:

" 45 ml., 237 C. 95 m1., 307 C.

After this material is added, refluxing is continued and, of course, isat a higher temperature, to wit, about to C. If the carboxyreactantisananhydride-needless to say no water of reaction appears;ifthe carboxy' reactant is an acid water ofreaction should appear andshould be eliminated at the above reaction temperature. If it .isnoteliminated I simply separate out another -10 or 20 cc. of benzene bymeans. of the -phase-separating' trap and thus raise the temperature to1 80 or'190"- C., or even to 200 C., if need be. My preference is not too above 200 C.

The use of such solvent is extremely satisfactory provided onedoes-notattempt to remove the solvent subsequently except by vacuumdistillation andprovidedthere is no objection to a main. If the solventis to be removed by distillation, and particularly vacuum distillation,then the high boiling aromatic petroleum solvent might well be replacedby some more expensive 10 positions are still obscure. Such sidereaction products can contribute a substantial proportion of the finalcogeneric reaction mixture. Various suggestions have been made as to thenature of solvent, such as decalin or an alkylated decalin thesecompounds, such as being cyclic polymers which has a rather definite orclose range boiling of propylene oxide, dehydration products with point.The removal of the solvent, of course, is the appearance of a vinylradical, or isomers of purely a conventional procedure and requires nopropylene oxide or derivatives thereof, i. e., of an elaboration.aldehyde, ketone, or allyl alcohol. In some in- In the appended tableSolvent #7-3, which apstances an attempt to react the stoichiometricpears in numerous instances, is a mixture of 7 amount of a polycarboxyacid with the tetralol volumes of the aromatic petroleum solventpreresults in an excess of the carboxylated reactant viously-describedand 3 volumes of benzene. Reffor the reason that apparently underconditions erence to Solvent #7 means the particular peof reaction lessreactive hydroxyl radicals are troleum solvent previously described indetail. present than indicated by the hydroxyl value. This was used, ora similar mixture, in the man- Under such circumstances there is simplya resiner previously described. A large number of the due of thecarboxylic reactant which can be reexamples indicated were repeatedemploying moved by filtration or, if desired, the esterificadecalin,using this mixture and particularly with lo procedure n b r p u in anppr the preliminary step of removing all the water. 2 priately reducedratio of carboxylic reactant. If one does not intend to remove thesolvent my Even the determination of the hydroxyl value preference is touse the petroleum solventby conventional procedure leaves much to bedebenzene mixture although obviously any of the sired due either to thecogeneric materials preother mixtures, such as decalin and xylene, canviously referred to, or for that matter, the pres b employed, 2;; enceof any inorganic salts or propylene oxide.

The data included in the subsequent table are Obviously this oxideshould be eliminated. self-explanatory, and very complete and it is Thesolvent employed, if any, can be removed believed no further elaborationis necessary: from the finished ester by distillation and par- TABLE IAmt.

of 1\1Igax. Tiifne Ex. Theo Poly- 5- o No. No.0f M01. "9%; Polycarcar-SOL teri- ES:- \Vatcr of Acid Hy- Wt. of o l I boxy Reactboxy Vent Ventficateri- Out Ester droxy Tetmo ant Rers) tion fica- (00.) Ompd. ralol@1115) act- 5 Temp, tion ant 0. (hrs) (a e) lb la 2,173 100 Diilyicol a#7-3 120 190 15 3.0

01 2b 1a 2,173 100 Phthalic 26.6 #7-3 125 175 5 Nil Anhyd 3b la 2,173100 Maleic 17.6 #7-3 116 170 4% N11 Anhyd. 4b 141 2,173 100 Succinic 18#7-3 116 165 4% Nil Anhyd. 5b la 2,173 100 Aconitic 32 #7-3 122 182 43.0

Acid.

suming complete combination with the glycide.

The procedure for manufacturing the esters has been illustrated bypreceding examples. If for any reason reaction does not take place in amanner that is acceptable, attention should be directed to the followingdetails: (a) Rechecs: the hydroxyl or acetyl value of the tetralol anduse a stoichiometrically equivalent amount of acid; (b) if the reactiondoes not proceed with reasonable speed either raise the temperatureindicated or else extend the period of time up to 12 or 16 hours if needbe; (c) if necessary, use /2% of paratoluene sulfonic acid or some otheracid as a catalyst; (d) if the esterification does not produce a clearproduct a check should be made to see if an inorganic salt such assodium chloride or sodium sulfate is not precipitating out. Such saltshould be eliminated, at least for exploration experimentation, and canbe removed by filtering. Everything else being equal as the size of themolecule increases the reactive hydroxyl radical represents a smallerfraction of the entire molecule and thus more difiiculty involved inobtaining complete esterification.

Even under the most carefully controlled conditions of oxypropylationinvolving comparatively low temperatures and long time of reaction thereare formed certain compounds Whose comticularly vacuum distillation. Thefinal products or liquids are generally almost Water-white to a verypale straw color, and show moderate viscosity. They can be bleached withbleaching clays, filtering chars, and the like. However, for the purposeof clemulsification or the like color is not a factor and decolorizationis not justified.

In the above instance I have permitted the solvents to remain present inthe final reaction mass. In other instances I have followed the sameprocedure using decalin or a mixture of decalin or benzene in the samemanner and ultimately removed all the solvents by vacuum distillation.

PART 3 In the hereto appended claims the demulsifying agent is describedas an acidic ester obtained from a material having 4 hydroxyl radicals.The tetralol used to produce the ester is, in turn, obtained from apolypropylene glycol.

Oxypropylation is obviously involved in the preparation of high molalpolypropylene glycols of the kind herein employed as raw materials.Propylene glycol has a secondary alcoholic radical and a primary alcoholradical. Obviously then polypropylene glycols could be obtained, atleast theoretically, in which two secondary al- 11. coholic groups areunited or a secondary alcohol group is united to a primary alcoholgroup, etherization being involved,-of course, in each instance.Needless to say, the same situation applies when one reacts such glycolsto produce polyhydric materials having/1'01 more hydroxyls.

As was previously noted; polypropylene glycols are obtained by theoxypropylation of water or propylene glycol, orthe equivalent. The usualmethod is to oxypropylate propylene glycol, or dipropylene glycol forthat matter. Usually no effort is made to differentiate betweenoxypropylation taking place, for example, at the primary alcohol unitradical or the secondary alcohol radical. Actually, when such productsare obtained; such as a high molal polypropylene glycol or the productsobtained in themanner herein described one does not obtain a singlederivative such as HO(RO)nI-I or --(RO)nH in which n has one andonly'one value, for'instance, 14, or 16, or the like. Rather, oneobtains a cogeneric mixture of closely related or touching homologues.These materials invariably have high molecular weights and cannot beseparated from one another by any known procedure without decomposition.The properties of such mixture represent the contribution of the variousindividual members of the mixture. On a statistical basis, of course, ncan be appropriately specified. For practical purposes one need onlyconsider the oxypropylation of a monohydric alcohol because in essencethis is substantially the mechanism involved. Even in such instanceswhere one is concerned with a monohydric reactant one cannot draw asingle formula and say that by following such procedure one can readilyobtain 80% or 90% or 100% of such compound. However, in the case of atleast monohydric initial reactants one can readily draw the formulas ofa large number of compounds which appear in some of the probablemixtures or can be prepared as components and mixtures which aremanufactured conventionally.

Simply by way of illustration reference is made to the copendingapplication of De Groote, Wirtel and Pettingill, Serial No. 109,791,filed'August 11, 1949 (now Patent 2,549,434, granted April 1'7, 1951).

However, momentarily referring again to a monohydr-ic initial reactantit is obvious that if one selects any such simple hydroxylatedcoinpoundand subjects such compound to oxyalkylation, such asoxyethylation, or oxypropylation, it becomes obvious that one is reallyproducing a polymer of the alkylene oxides except for the terminal;group. This is particularly truewhere the amount of oxide added iscomparatively large, for instance, 10,20, 30, 40, or 50 units. If suchcompound is subjected to oxyethylation so as to introduce unitsofethylene oxide, it is well known that one does not obtain a singleconstituent which, for the sake of convenience, may be indicated asRO(C2H4O) 30H. Instead, one obtains a cogeneric mixture of closelyrelated homologues, in which the formula may be shown as the following,RO(C2H40)nH, wherein n, as far as the statistical average goes, is 30,but the individual members present in significant amount may vary frominstances where n has a value .of 25, and perhaps less, to a point where11, may represent or more. Such mixture is, as stated, a .cogenericclosely related series .of touching homologous compounds; Considerable.investigation. has been made in regard to the distribution,

curves for linear polymers. Attention is directed to the articleentitled Fundamental Principles of Condensation Polymerization,by'Flory, which necessary to'resort to some'other method of'description, or else" consider the value of n, in formulas such asthose which have appeared previously and which appear inthe claims, as

representing both individual constituents in which n'has. asingledefinitevalue, and also with the understandingth at n representsthe average'stae tistical value based on the 'assumptionof completenessof reaction,

As far as the polypropylene glycol is concerned, as previously stated,one, could start withwater or propylene glycol and react the productwithlZ to moles of propylene oxide in order to have a suitable reactantfor combination with glycide. Assume in a'particular example that acombination takes place so that 15 moles of propylene oxide are used foran initial mole of water. In a generic formula for a propyleneglycoLsuch as HO(RO)nI-I previously employed, n can vary as noted andmight be 15, 20,30, 40 or morei Referring to a specific case where '15moles of propylene oxide are combined with one mole of water to give apolypropylene'glycol actually one obtains products in-whichn probablyvaries from 10 to 20, perhaps even further. value, however, is I 15,assuming, as previously stated, that thereaction is complete. Theprodnot described by 'theformula is best described by.

a suitable formulawhich includesvarious isomers without differentiationor also in terms of method of manufacture.

The significant fact is in regard to the glycerol or glycide ethers ofthe polypropylene glycols herein specified that although they areobtained from initial products which are water-soluble, i. e., water,propylene glycol or the like, yet these tetralols prior toesterificationare water-insoluble and kerosene-soluble. Needless to say,treatment of any chemical compound with 1, 2 or 3 moles of glycide tendsto increase water-solubility and decrease kerosene-solubility.Incidentally, too, the initial products prior to oxypropylation are notxylene-soluble, that is; water and propylene glycol are notxylene-soluble, but the final prod- Going back to what has been saidpreviously" in the introductory part it will be noted that, .one mayhave variations in regard to how the The average glycide combines toform the tetralol. Thus, the formula as herein employed and particularlythe claims, must be interpreted in light of the facts previouslyindicated namely (a) there may be a considerable variation in thestructure of a polypropylene glycol as to whether one has a headto-tailstructure, a tail-to-tail structure, or a head-tohead structure, orother variations; (1)) variation will take place in the total range, forexample, in an instance where n might statistically average 40 theactual variation of n might run from to 60, and (c) the manner in whichthe glycide combines to produce a tetralol may vary also as has beenpointed out. These facts must be considered in the descriptions hereinemployed, both in the specification and in the claims. For obviousreasons no better characterization is available.

PART 4 Conventional demulsifying agents employed in the treatment of oilfield emulsions are used as such, or after dilution with any suitablesolvent, such as water, petroleum hydrocarbons, such as benzene,toluene, xylene, tar acid oil, cresol,

anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such asmethyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, butylalcohol, hexyl alcohol, octyl alcohol, etc, may be employed as diluents.Miscellaneous solvents such as pine oil, carbon tetrachloride, sulfurdioxide extract obtained in the refining of petroleum, etc., may beemployed as diluents. Similarly, the material or materials employed asthe demulsifying agent of my process may be admixed with one or more ofthe solvents customarily used in connection with conventionaldemulsifying agents. Moreover, said material or materials may be usedalone or in admixture with other suitable wellknown classes ofdemulsiiying agents.

It is well known that conventional demulsify" ing agents may be used ina water-soluble form, or in an oil-soluble form, or in a form exhibitingcoth oiland water-solubility. Sometimes they may be used in a form whichexhibits relatively limited oil-solubility. However, since such reagentsare frequently used in a ratio of 1 to 10,000 or 1 to 20,000, or 1 to30,000, or even 1 to 40,000, or 1 to 50,000 as in desalting practice,such an apparent insolubility in oil and water is not significantbecause said reagents undoubtedly have solubility within suchconcentration. This same fact is true in regard to the material ormaterials employed as the demulsifying agent of my process.

In practicing my process for resolving petroleum emulsions of thewater-in-oil type, a treating agent or demulsifying agent of the kindabove described is brought into'contact with or caused to act upon theemulsion to be treated, in any of the various apparatus now generallyused to resolve or break petroleum emulsions with a chemical reagent,the above procedure being used alone or in combination with otherdemulsifying procedure, such as the electrical dehydration process.

One type of procedure is to accumulate a volume of emulsified oil in atank and conduct a batch treatment type of demulsification procedure torecover clean oil. In this procedure the emulsion is admixed with thedemulsifier, for example by agitating the tank of emulsion and slowlydripping demulsifier into the emulsion. In some cases mixing is achievedby heating the emulsion while dripping in the demulsifier, dependingupon the convection currents in the emulsion to produce satisfactoryadmixture. In a third modification of this type of treatment, acirculating pump withdraws emulsion from, c. g., the bottom of the tank,and reintroduces it into the top of the tank, the demulsifier beingadded, for example, at the suction side of said circulating pump.

In a second type of treating procedure, the demulsifier is introducedinto the well fluids at the well-head or at some point between thewell-- head and the final oil storage tank, by means of an adjustableproportioning mechanism or proportioning pump. Ordinarily the flow offluids through the subsequent lines and fittings suffices to produce thedesired degree of mixing of demulsifier and emulsion, although in someinstances additional mixing devices may be introduced into the flowsystem. In this general procedure, the system may include variousmechanical devices for withdrawing free water, separating entrainedwater, or accomplishing quiescent settling of the chemicalized emulsion.Heating devices may likewise be incorporated in any of the treatingprocedures described herein.

A third type of application (down-the-hole) of demulsifier to emulsionis to introduce the demulsifier either periodically or continuously indiluted or undiluted form into the well and to allow it to come to thesurface with the well fluids, and then to flow the chemicalized emulsionthrough any desirable surface equipment, such as employed in the othertreating procedures. This particular type of application is decidedlyuseful when the demulsifier is used in connection with acidification ofcalcareous oil-bearing strata, especially if suspended in or dissolvedin the acid employed for acidification.

In all cases, it Will be apparent from the foregoing description, thebroad process consists simply in introducing a relatively smallproportion of demulsifier into a relatively large proportion ofemulsion, admixing the chemical and emulsion either through natural flowor through special apparatus, with or without the application of heat,and allowing the mixture to stand quiescent until the undesirable Watercontent of the emulsion separates and settles from the mass.

The following is a typical installation.

A reservoir to hold the demulsifier of the kind described (diluted orundiluted) is placed at the well-head Where the efiiuent liquids leavethe well. This reservoir or container, which may vary from 5 gallons to50 gallons for convenience, is connected to a proportioning pump whichinjects the demulsifier drop-wise into the fluids leaving the well. Suchchemicalized fluids pass through the fiowline into a settling tank. Thesettling tank consists of a tank of any convenient size, for instance,one which will hold amounts of fluid produced in 4 to 24 hours (500barrels to 2000 barrels capacity), and in which there is a perpendicularconduit from the top of the tank to almost the very bottom so as topermit the incoming fluids to pass from the top of the settling tank tothe bottom, so that such incoming fluids do not disturb stratificationwhich takes place during the course of demulsification. The settlingtank has two outlets, one being below the water level to drain off thewater resulting from demulsification or accompanying the emulsion asfree water, the other being an oil outlet at the top to permit thepassage of dehydrated oil to a second tank, being a storage tank, whichholds pipeline or dehydrated oil. If desired, the conduit or pipe whichserves to carry the fluids from the well to the settlingtank mayincludeza sec-.-

tion of-pipe with baifies ;to-, serve as amixer, ,to insure thoroughdistribution of 'the demulsifier throughout the fluids',-or a heater forraising the. temperature ofthe fluids to someconvenient:

temperature, for instance,- 120" to 160 F.-, or both heater and mixer.

Demulsification procedure is started by simply setting'the pump-so as tofeed a--comparativelylarge ratio of demulsifier, for instance,1:5,000';- As soon as a complete break or satisfactory demulsificationisob-tained the pumpfis regulated until experience shows a that the amountof-dermulsifier being added isrjust'sufficient to'produce clean ordehydrated oil. The amount being; fed at such-stage is usually 1110,000,1215,000;

1 :20,000,:or the like.

Inmany instances theoxyalkylatedproducts;

herein specified as .demulsifiers can lee-conveniently used withoutdilution. However, as iprevie.

ously-noted, they may Ice-diluted as desirediwithany suitable solvent.For instance, by mixingifld parts by weight of theproduct of Example-2bwith 15 parts by-Weight of xylene and -10-parts by Weight ofisopropyl alcohol; an-excellent-flemulsifier is obtained. Selection ofthe-solvent will. vary, depending upon the solubilitycharacteristics. ofthe'oxyalkylated product, andof:

coursewill be dictated in part by economicconsiderations, i. e.; cost.

As noted above, theproducts herein described 1 may be used not only indiluted form, but also may be used admixed with: some other chemicaldemulsifier. combination is the following:

Oxyal-kylatedderivative; f or example,- the prodnot of Example 2b,

A cy-clohexylamine salt -of a polypr-opyla-ted naphthalene monosulfonicacid, 24%;

Anammonium salt of a pclypropylated-naphthalene mono-sulfonic acid, 24%;

A sodium salt of oil-soluble mahoganypetroleum-sulfonic acid, 12%;

A high-boiling aromatic petroleum solvent,- 15

Isopropyl-alcohol; 5

The above proportions are all weight-percents- PART 5 Previous reierencehas been made to oxyalkyl ated agents other than propyleneoxide-and glycide; for example, ethylene oxide land-butylene oxide; Obviouslyvariants can be-prepared whicn do not depart from What hasbeen saidherein ,-toproduce compounds of' the described structure:

A mixturewhich illustrates: such.

The tetralo'lscould be treatedwith-oneor more moles of ethylene .oxideto" yield a produot in which water-solubility and kerosene-solubilityhave not been particularly afiected. Such=tetralol couldthen be combinedto give the acidicfractional ester corresponding to thosehereindescribed. The molecular weight range of the-tet--- ralolwould:obviously be within the described-1M1- Instead of ethylene oxideone-might emplov its.

butyleneoxide In such variations other comparable ones can be employedwithout departingfrom the spirit of the invention;

Incidentally, the polyhydroxylated. materials described in Part 1 canbetreated with variousreactants such as epichlorohydrin, dimethylsulfate, sulfuric acid, ethylene imine, etc., to givenew intermediate ofobvious value. for.organicj If treated with .epichlorohydrinzior;monochloracetic acid the resultant productcan'; be further reacted withatertiary amine; suchsynthesis.

16? as...pyridine, or the like, to .give 1 ammonium:.com-. pounds. Iftreated .witlrmaleicanhydride to give a total. ester the resultant canbe treated with sodium bisulfite to yield a sulfosuccinate; Sulfo groupscan beintroduced also by means of a sulf-ating agent as previously.suggested, or by treating the chloroacetic acid resultant with sodiumsulfite.

I have found that if such hydroxylated compound or compoundsare reactedfurther so as to produce entirely new derivatives; such new derivativeshave-the properties of the original hydroxylated compound to some degreeand yet in other ways are markedly different; This is especiallytrue-insofar that they are effective and valuable demulsifying agentsin'manyinstances forresolutionof water-in-oil emulsions as found in' thepetroleum industry, as break-inducers in doctor treatment of sour crude,etc.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. Aprocess for breaking petroleum emulsions.

of the water-in-oil.typecharacterized by subjecting the emulsion to theaction of a demulsifier including hydrophile synthetic products; saidhydrophile synthetic products. beingacharacter ized by the formula and(R0) n is the divalent radical of apolyprop-ylene glycol of thestructure I-IO(RO)nH, with the proviso that n be a whole number soselected, that the polypropylene glycol be within the approximatemolecular weight range of 750 to 5,000; n is a whole number not greaterthan-2, and'n" is a whole number varying from 1 to 3 with'the limitationthat the sum of n" plus n be 4; and R" is the radical of the polycarboxyacid COOH with the further proviso that the parent tetralol prior toesterification be water-insoluble and kerosene-soluble.

2. A process for breaking petroleum emulsions of thewater-in-oil typecharacterized by subjectngtheemulsion to the action ofa .demulsifierincluding hydrophile synthetic products; said hydrophile. syntheticproducts being characterized by the formula 17 in which R"'O(RO)1R"' isa tetravalent radical obtained by the elimination of the hydroxylhydrogen atoms from the tetralol R'O(RO)11R' in which R is a monovalentradical selected from the class consisting of hydrogen,

H and OH ciHt OH OC8H5 and (B0) is the divalent radical of apolypropylene glycol of the structure HO(RO)1|.H, with the proviso thatn be a whole number so selected, that the polypropylene glycol be withinthe approximate molecular weight range of 1750 to 2750; n is a wholenumber not greater than 2, and n is a whole number varying from 1 to 3with the limitation that the sum of n" plus n" be 4; and R" is theradical of the polycarboxy acid coon with the further proviso that theparent tetralol prior to esterification be water-insoluble andkerosene-soluble.

3. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsiflerincluding hydrophile synthetic products;

said hydrophile synthetic products being characterized by the formula 0nooown'w z R"'O(RO),,R' m'moooma il in which R'O(RO)1,R is a tetravalentradical obtained by th elimination of the hydroxyl hydrogen atoms fromthe tetralol R.O(RO)nR' in which R is a monovalent radical selected fromthe class consisting of hydrogen,

CaHs

and

OCIHI and (B0) is the divalent radical of a polypropylene glycol of thestructure HO(RO)11H, with the proviso that n be a whole number soselected, that the polypropylene glycol be within the approximatemolecular range of 1750 to 2750; n is a whole number not greater than 2,and n" is a whole number varying from 1 to 3 with the limitation thatthe sum of 11." plus n" be 4; and R" is the radical of the polycarboxyacid COOK 18 having not over 8 carbon atoms; and with the furtherproviso that the parent tetralol prior to esterification bewater-insoluble and kerosenesoluble.

4. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being characterized by the formula in which R"O(R;O)1R"' is atetravalent radical obtained by the elimination of the hydroxyl hydrogenatom from the tetralol R'O(RO)nR in which R is a monovalent radicalselected from the class consisting of hydrogen,

CaHs

and

0 H czfln and (ROM is the divalent radical of a polypropylene glycol ofthe structure HO(RO)1:H, with the proviso that n be a whole number soselected, that the polypropylene glycol be within the approximatemolecular weight range of 1750 to 2750; n" is a whole number varyingfrom 1 to 3 with the limitation that the sum of n" plus n" be 4; and R."is the radical of the dicarboxy acid coon REFERENCES CITED The followingreferences are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,552,528 De Groote May 15, 19512,562,878 Blair Aug. 7, 1951

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPECHARACTERIZED BY SUBJECTING THE EMULSION OT THE ACTION OF A DEMULSIFIERINCLUDING HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETICPRODUCTS BEING CHARACTERIZED BY THE FORMULA